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Discussion Starter · #1 ·
Hello all, Newbie here! Have a 2000 lesabre - has been running great up till about a week ago. Lately it runs great when started cold and run till I shut it down. When it is started 'hot' it cuts out randomly. It will idle rough intermittently, or die completely. When driving at 65 it will drop rpm for a split second and jerk the car.... I started by changing the fuel filter but wondering if it could be the fuel pressure sensor or the fuel pump. Can the fuel pump reduce pressure over time and cause this? or would the fuel pump just quit altogether? Is there a way i could check pressure at the engine? No service engine light on at this point... Any ideas would be very helpful... appreciate any tips in advance!
 

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The description you gave about how it "cuts out" does not fit a fuel pump issue. It sounds more like a MAF sensor. If you unplug this sensor (mounted in the throttle housing) and the condition goes away, there you go. If you do find this, DO NOT BUY a REBUILT one. Approx 100% of the remans available today are junk. The best band for the buck right now is a DORMAN SELECT. These are new and a lot cheaper the the OE ones.

I would also strongly suggest you scan the computer controls or have it done for you before you start spending money for a part that may not be bad........

Good luck, Jake L.

PS, next time you shut it off, pull the vacuum line off the fuel pressure regulator to see if any fuel at all might be leaking...... Replace this before doing anything else if it's leaking ta all......
 

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X2!! Great advice!
 

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Discussion Starter · #4 ·
Thank you very much for the info! Last night the service engine light came on, I read code and it pointed to MAF sensor... Cleaned it with MAF sensor cleaner and hasn't fixed it. Will need to buy a new one! Thanksalot for the advice!!
 

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It would be worth getting the fuel pressure tested. A bad pump can cause intermittent "hot" problems like you describe. If the pump can't keep a high enough pressure, you can get a vapor lock when the engine is hot.

And yes, a pump doesn't necessarily just fail all together. I had a 1992 Buick Century that had this similar problem. It would sometimes run great for weeks at a time, then stall randomly and not start.

At worst, checking the fuel pressure will allow you to rule it out as the culprit.
 
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